PHP ─ Date and Time

Dates are so much part of everyday life that it becomes easy to work with them without thinking. PHP also provides powerful tools for date arithmetic that make manipulating dates easy.

Getting the Time Stamp with time()

PHP's time() function gives you all the information that you need about the current date and time. It requires no arguments but returns an integer.

The integer returned by time() represents the number of seconds elapsed since midnight GMT on January 1, 1970. This moment is known as the UNIX epoch, and the number of seconds that have elapsed since then is referred to as a time stamp.


It will produce the following result:


This is something difficult to understand. But PHP offers excellent tools to convert a time stamp into a form that humans are comfortable with.

Converting a Time Stamp with getdate()

The function getdate() optionally accepts a timestamp and returns an associative array containing information about the date. If you omit the time stamp, it works with the current time stamp as returned by time().

The following table lists the elements contained in the array returned by getdate().

Key	Description	Example
seconds	Seconds past the minutes (0-59)	20
minutes	Minutes past the hour (0 - 59)	29
hours	Hours of the day (0 - 23)	22
mday	Day of the month (1 - 31)	11
wday	Day of the week (0 - 6)	4
mon	Month of the year (1 - 12)	7
year	Year (4 digits)	1997
yday	Day of year ( 0 - 365 )	19
weekday	Day of the week	Thursday
month	Month of the year	January
0	Timestamp	948370048

Now you have complete control over date and time. You can format this date and time in whatever format you want.

Example

Try out the following example.


It will produce the following result:


Converting a Time Stamp with date()

The date() function returns a formatted string representing a date. You can exercise an enormous amount of control over the format that date() returns with a string argument that you must pass to it.


The date() optionally accepts a time stamp if omitted, then current date and time will be used. Any other data you include in the format string passed to date() will be included in the return value.

The following table lists the codes that a format string can contain:

Format	Description	Example
a	'am' or 'pm' lowercase	pm
A	'AM' or 'PM' uppercase	PM
d	Day of month, a number with leading zeroes	20
D	Day of week (three letters)	Thu
F	Month name	January
h	Hour (12-hour format - leading zeroes)	12
H	Hour (24-hour format - leading zeroes)	22
g	Hour (12-hour format - no leading zeroes)	12
G	Hour (24-hour format - no leading zeroes)	22
i	Minutes ( 0 - 59 )	23
j	Day of the month (no leading zeroes	20
l (Lower 'L')	Day of the week	Thursday
L	Leap year ('1' for yes, '0' for no)	1
m	Month of year (number - leading zeroes)	1
M	Month of year (three letters)	Jan
r	The RFC 2822 formatted date	Thu, 21 Dec 2000 16:01:07 +0200
n	Month of year (number - no leading zeroes)	2
s	Seconds of hour	20
U	Time stamp	948372444
y	Year (two digits)	06
Y	Year (four digits)	2006
z	Day of year (0 - 365)	206
Z	Offset in seconds from GMT	+5

Example

Try out the following example.


It will produce following result:


Hope you have a good understanding of how to format date and time according to your requirement. For your reference a complete list of all the date and time functions is given in PHP Date & Time Functions.

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